Determining standards for professional divers diving in benzene polluted waters.

Area of Science:

• Occupational health
• Environmental toxicology
• Marine biology

Background:

• Benzene exposure poses risks to professional divers in polluted waters.
• Existing occupational exposure limits are primarily for inhalation during an 8-hour workday.
• Diving environments present unique exposure routes including dermal and potential ingestion.

Purpose of the Study:

• To calculate acceptable diving hours for professional divers in benzene-contaminated waters.
• To develop a formula for determining safe diving time based on benzene concentrations.
• To establish a benzene absorption limit equivalent to workplace pulmonary exposure limits.

Main Methods:

• Utilized the National Institute for Occupational Safety and Health (NIOSH) recommended exposure limits (RELs).
• Developed a formula incorporating water and sediment benzene concentrations, and dermal/gastrointestinal exposure.
• Calculated equivalent benzene absorption for various exposure scenarios (diving, drinking, sediment contact).

Main Results:

• The recommended total body absorption limit for benzene is 1.6 mg per workday.
• This limit is equivalent to a 1-hour dive in water with 7.6 mg/L benzene.
• Water concentration, not sediment, is the primary factor limiting safe diving time.

Conclusions:

• Allowable diving time in polluted waters can be calculated to match safe workplace pulmonary absorption limits.
• Findings suggest that even unlimited diving in some hazardous areas may not exceed workplace benzene absorption limits.
• Agencies should consider these findings when setting health risk levels for water and sediment contaminants.